Im trying to get sliding working on my 3d game

So I’m trying to make sliding in my 3d game but I can’t get it to move the way the player is facing, any one got any way to fix it? - code (leftcontrol is sliding):
`using System.Collections;
using System.Collections.Generic;
using UnityEngine;

[RequireComponent(typeof(CharacterController))]
public class PlayerMovement : MonoBehaviour
{
public Camera playerCamera;
public float walkSpeed = 6f;
public float runSpeed = 12f;
public float jumpPower = 7f;
public float gravity = 10f;
public float lookSpeed = 2f;
public float lookXLimit = 45f;
public float defaultHeight = 2f;
public float crouchHeight = 1f;
public float crouchSpeed = 16f;

private Vector3 moveDirection = Vector3.zero;
private float rotationX = 0;
private CharacterController characterController;

private bool canMove = true;

void Start()
{
    characterController = GetComponent<CharacterController>();
    Cursor.lockState = CursorLockMode.Locked;
    Cursor.visible = false;
}

void Update()
{
    Vector3 forward = transform.TransformDirection(Vector3.forward);
    Vector3 right = transform.TransformDirection(Vector3.right);

    bool isRunning = Input.GetKey(KeyCode.LeftShift);
    float curSpeedX = canMove ? (isRunning ? runSpeed : walkSpeed) * Input.GetAxis("Vertical") : 0;
    float curSpeedY = canMove ? (isRunning ? runSpeed : walkSpeed) * Input.GetAxis("Horizontal") : 0;
    float movementDirectionY = moveDirection.y;
    moveDirection = (forward * curSpeedX) + (right * curSpeedY);

    if (Input.GetButton("Jump") && canMove && characterController.isGrounded)
    {
        moveDirection.y = jumpPower;
    }
    else
    {
        moveDirection.y = movementDirectionY;
    }

    if (!characterController.isGrounded)
    {
        moveDirection.y -= gravity * Time.deltaTime;
    }

    if (Input.GetKey(KeyCode.LeftControl))
    {
        characterController.height = crouchHeight;
        walkSpeed = crouchSpeed;
        runSpeed = crouchSpeed;
        
    }
    else
    {
        characterController.height = defaultHeight;
        walkSpeed = 6f;
        runSpeed = 12f;

    }
    if (Input.GetKey(KeyCode.LeftControl))
    {
        if (Input.GetKeyDown(KeyCode.LeftControl));

    }
    else
    {
        canMove = true;
    }
    characterController.Move(moveDirection * Time.deltaTime);

    if (canMove)
    {
        rotationX += -Input.GetAxis("Mouse Y") * lookSpeed;
        rotationX = Mathf.Clamp(rotationX, -lookXLimit, lookXLimit);
        playerCamera.transform.localRotation = Quaternion.Euler(rotationX, 0, 0);
        transform.rotation *= Quaternion.Euler(0, Input.GetAxis("Mouse X") * lookSpeed, 0);
    }
}

}`